How Logistep catches file sharers

[Osiris]

It is no secret that companies like Logistep are monitoring p2p networks to sue file sharers who are offering software from clients like Zuxxez, a German company who recently sued 500 British p2p users claiming that they illegally distributed the game Dream Pinball 3D. The website Torrentfreak got their hands on a copy of one of those letters that have been send out which details the process of how Logistep determines which users are illegally distributing the game.
Logistep uses a software called File Sharing Monitor that targets E-Donkey and Gnutella users. Here is how it works:

• The software connects to a p2p server and requests a filename recording all IP addresses that offer that name
• They request to download the file and if the download is permitted record the following information into a database
• Filename, file size, IP of the distributor, P2P protocol, P2P application, the time and the username
• When this is inserted the application does a automatic whois and is able to send an infringement letter to the ISP

I think it is interesting to note that this is almost an automatic process which leads to some questions. How do they know which archive has the correct size and is actually their product and not a broken archive ? Is not it only possible to know the exact file size if they downloaded it at least once to verify that is is indeed their product ?
Let us assume that they are not stupid and that they filter out every file below a certain size to prevent that users who do share mods or patches get sued. Let us further assume that a file that is labeled a certain way (with group tags) and shared among many users is the right program. Does this mean that the user that they are suing is responsible ? They will always sue the account holder which could or could not be the person who shared the files.
What possible solutions can I think of that make the Logistep file monitor useless ? Please note that this is hypothetic, I’m not advising anyone to actually use the methods listed below.

• don’t share files
• share only files with no plausible filename (3dpd)
• use encryption to share the files
• use vpns like Relakks to share them
• switch to Usenet
• buy the game http://www.ghacks.net/wp-includes/im.../icon_wink.gif

Can you think of anything else left to say ?